1. Field of the Invention
The present invention relates to a liquid discharge apparatus which discharges a liquid.
2. Description of the Related Art
An ink jet type recording apparatus is known as an example of the liquid discharge apparatus which discharges a liquid (ink), including a recording head which has a discharge surface formed with a plurality of nozzles for discharging the ink, a recording control mechanism which controls the recording operation for performing the recording by driving the recording head and discharging the ink from the nozzles to the recording medium, and a flushing control mechanism which allows the ink to be discharged from the nozzles by driving the recording head distinctly from the recording operation. The known ink-jet type recording apparatus is provided with the recording head having a plurality of ink manifolds which extend in the extending direction, which are provided with an ink supply port disposed on one end side in the extending direction, and which are communicated with the respective nozzles, and a communication channel which is provided on the other end side in the extending direction of the plurality of ink manifolds and which makes communication between the plurality of ink manifolds (see Japanese Patent No. 3036548).
In such an arrangement, the plurality of ink manifolds are provided for the recording head and the communication channel is provided to make communication between the plurality of ink manifolds for the purpose of mitigating harmful effects of the water hammer phenomenon. In the recording head, the execution of ink discharge and the stop of ink discharge are intermittently repeated in order to perform the recording. In such a situation, if the terminal end of the ink manifold is closed, the water hammer phenomenon arises such that the pressure wave, which is generated by the repetition of the ink discharge, is transmitted through the ink channel. However, when the communication channel is provided at the terminal end of the ink manifold, then the pressure wave is also transmitted to the interior of the communication channel, the pressure wave is weakened, and it is possible to mitigate the harmful effects of the water hammer phenomenon. In this arrangement, the communication channel is communicated with dummy nozzles formed on the discharge surface of the recording head. The liquid droplets are not discharged from the dummy nozzles during the recording operation. The ink is merely discharged during the purge operation in order to maintain the performance for discharging the ink. Therefore, the ink contained in the communication channel remains in such a state that the ink stays and stops in the communication channel during any period other than the period in which the purge operation is performed.